The purpose of this study is a) to determine the pharmacokinetics of RP59500 synercid and compare the pharmacokinetic profile after single and multiple doses in volunteers with moderate or severe chronic renal failure, and b) to assess the clinical and biological tolerability of multiple doses of RP59500 Synercid in these same subjects. The subjects will be admitted to the GCRC and receive multiple infusions of the drug. Serial blood specimens will be obtained and analyzed for drug concentration by the investigator.